signal box

a railway signal tower.

Origin of signal box

First recorded in 1820–30

"Twelve thirteen," said Peter, and indeed it was by the white-faced, round-faced clock on the wall of the signal-box.

The Railway Children |E. Nesbit
The roof of the porch is cut from cardboard, with flanges to be glued to the end of the signal-box.

Toy-Making in School and Home |Ruby Kathleen Polkinghorne and Mabel Irene Rutherford Polkinghorne
He gave them each an orange, and promised to take them up into the signal-box one of these days, when he wasn't so busy.

The Railway Children |E. Nesbit
And you and Inspector Henderson are going to spend the night in the signal-box?

A Master of Mysteries |L. T. Meade

Fairfax came up with the signal-box by the swinging gate, and a man with a rolled red flag stood in the doorway.

Fairfax and His Pride |Marie Van Vorst

signal box

a building containing manually operated signal levers for all the railway lines in its section

a control point for a large area of a railway system, operated electrically and semiautomatically